A comparative computational study of diesel steam reforming in a catalytic plate heat‐exchange reactor

A two‐dimensional steady‐state model of a catalytic plate reactor for diesel steam reforming is developed. Heat is provided indirectly to endothermic reforming sites by flue gas from a SOFC tail‐gas burner. Two experimentally validated kinetic models on diesel reforming on platinum (Pt) catalyst were implemented for a comparative study; the model of Parmar et al., Fuel. 2010;89(6):1212–1220 for a Pt/Al₂O₃ and the model of Shi et al., International Journal of Hydrogen Energy. 2009;34(18):7666–7675 for a Pt/Gd‐CeO₂ (GDC). The kinetic models were compared for: species concentration, approach to equilibrium, gas hourly space velocity and effectiveness factor. Cocurrent flow arrangement between the reforming and the flue gas channels showed better heat transfer compared to counter‐current flow arrangement. The comparison between the two kinetic models showed that different supports play significant role in the final design of a reactor. The study also determined that initial 20% of the plate reactor has high diffusion limitation suggesting to use graded catalyst to optimize the plate reactor performance. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1102–1113, 2017     

Influence of heat input on microstructure and fracture toughness property in different zones of X80 pipeline steel weldments

In this paper, microstructure observations and mechanical behaviour of fusion line and offsetting positions from fusion line by 1, 2 and 3 mm were analysed. For the welding of X80 pipeline steel plates, different magnitudes of heat inputs such as high heat input (HHI) 25 kJ/cm, medium heat input (MHI) 20 kJ/cm and low heat input (LHI) 15 kJ/cm were employed. Critical values of J‐integral (J_0.2) and crack tip opening displacement (CTOD_0.2) for predetermined regions in the X80 weldment were determined as per ASTM‐E1820a. M‐A constituents of different sizes such as small (1–2 μm), large >2 μm and slender (>4 μm) were observed in the microstructure of subzones of weldments for different heat inputs. Formation of granular bainite, M‐A constituents and inclusions of Ti, Si, Mo in the microstructure impaired fracture toughness property. In the X80 weldment, the fusion line (FL) for HHI was found weakest in terms of fracture resistance, which subsequently increases the risk of fracture.     

Oxidative Aminocarbonylation of Terminal Alkynes for the Synthesis of Alk‐2‐ynamides by Using Palladium‐on‐Carbon as Efficient,Heterogeneous, Phosphine‐Free,and Reusable Catalyst

Palladium‐on‐carbon (Pd/C)‐catalyzed oxidative aminocarbonylations of alk‐1‐ynes with secondary amines provide the corresponding alk‐2‐ynamides in a good to excellent yields. This new methodology is applicable for the synthesis of a wide range of biologically active alk‐2‐ynamide derivatives. The developed protocol avoids the use of phosphine ligands, with an additional advantage of palladium catalyst recovery and reuse for up to four consecutive cycles.     

Biopolymers as effective fillers in natural rubber: Composites versus biocomposites

Biocomposites of natural rubber (NR) blends were prepared with a variety of fillers obtained from renewable resources by a mastication technique. They were characterized for their mechanical properties and morphologies and compared with composites of the conventional filler carbon black (c‐black). The biopolymers exhibited an interesting trend and imparted strength to NR that was quite comparable to c‐black. Up to 30 phr of the fillers could be successfully incorporated; this led to enhancements in the mechanical strength. The properties were found to vary with the type and ratio of filler, namely, starch, cellulose, and chitin. The optimum mechanical strength of the biocomposites was observed at 10 phr. The results were interpreted on the basis of the morphology by scanning electron microscopy, which revealed strong filler–polymer interactions. The moisture‐uptake characteristics of the composites were studied. It was found that addition of biofillers did not lead to a significant increase in the moisture absorption. Furthermore, as the adhesion between the polymer matrix and fillers increased, the water uptake decreased. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

L-Arginine and Nitric Oxide in CNS Function and Neurodegenerative Diseases

One of the main functions of L-arginine (ARG) is the synthesis of nitric oxide (NO). NO is an important regulator of physiological processes in the central nervous system (CNS). NO promotes optimal cerebral blood flow, consolidates memory processes, facilitates long-term potentiation, maintains sleep-wake cycles, and assists in normal olfaction. However, at pathological levels, NO adversely affects brain function producing nitroxidative stress and promoting development of neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease and other disorders of the CNS. This review summarizes current knowledge of the role of NO in the CNS and the role of diet in regulating the levels of NO.     

Integrated Bioinformatics,Environmental Epidemiologic and Genomic Approaches to Identify Environmental and Molecular Links between Endometriosis and Breast Cancer

We present a combined environmental epidemiologic, genomic, and bioinformatics approach to identify: exposure of environmental chemicals with estrogenic activity; epidemiologic association between endocrine disrupting chemical (EDC) and health effects, such as, breast cancer or endometriosis; and gene-EDC interactions and disease associations. Human exposure measurement and modeling confirmed estrogenic activity of three selected class of environmental chemicals, polychlorinated biphenyls (PCBs), bisphenols (BPs), and phthalates. Meta-analysis showed that PCBs exposure, not Bisphenol A (BPA) and phthalates, increased the summary odds ratio for breast cancer and endometriosis. Bioinformatics analysis of gene-EDC interactions and disease associations identified several hundred genes that were altered by exposure to PCBs, phthalate or BPA. EDCs-modified genes in breast neoplasms and endometriosis are part of steroid hormone signaling and inflammation pathways. All three EDCs–PCB 153, phthalates, and BPA influenced five common genes—CYP19A1, EGFR, ESR2, FOS, and IGF1—in breast cancer as well as in endometriosis. These genes are environmentally and estrogen responsive, altered in human breast and uterine tumors and endometriosis lesions, and part of Mitogen Activated Protein Kinase (MAPK) signaling pathways in cancer. Our findings suggest that breast cancer and endometriosis share some common environmental and molecular risk factors.     

An efficient oxidative coupling of naphthols catalyzed by Fe impregnated pillared montmorillonite K10

Montmorillonite K10 was modified with pillaring solutions of Fe. The catalyst was activated at different temperatures. The resultant heterogeneous catalyst was used for coupling of 2-naphthol and derivatives under mild operating conditions. The activity of catalyst was compared with Fe pillared bentonite, Fe-exchanged montmorillonite K10 and bentonite catalysts. Amongst them, K10-FePLS120 showed better activity and selectivity. The catalyst can be recycled without loss of activity.     

Magnetic Force Microscopy of an Oxygen-Sensing Spin-Probe

In the present work we provide magnetic force microscopy (MFM) analysis on particles of a paramagnetic spin-probe lithium octa-n-butoxy-naphthalo-cyanine (LiNc-BuO) used for EPR oximetry. We demonstrate how MFM can generate a magnetic contrast in ambient air for LiNc-BuO particles when they assemble into structures >50 nm in size. The same sample when assembled into particles <10 nm in size failed to show contrast in MFM images. The potential for utilizing MFM to understand the magnetic signature of paramagnetic nanoparticles in biological samples is discussed.